I recently purchased a Cat 943 serial # 19Z00750. Since I have purchased it the Check light on the Control panel has quit working. Is this panel still available or can I convert to a gauge. Where on the engine would I get the oil pressure? This is my first post on this forum and my first Cat so hopefully I did this correctly.
Do the other lights on the EMS panel come on when you first turn the key on along with the Master Fault Light and the buzzer sounds.?
I'll let Nige take the lead on the troubleshooting. But I will give you major points for including the Model ans Serial Numbers right up front in the first post!!! One question I might ask is do you have at least the operators manual for this machine? If not first thing I would suggest is looking at the back of the operators seat, Cat often stuck them in a pouch on many machines there. Second this is if not on back of seat go to this site: https://www.servicemanualpro.com/ and enter your serial number and do a search. That will take you to the page where you can order the various manuals for your machine. Note the Operators manual is available as a down load for $42.00 so you can have it faster than I can type this reply. That will be one of the best $42.00 you can spend on this machine!
When I turn the main power switch key the power, (lightning bolt) flashes. No buzzer, no master fault light. I flip the test toggle switch and the coolant temp, lightning bolt and trans temp indicators flash. The oil pressure does not flash. Notr does the buzzer or the master fault light.
Thank you. I will do this tomorrow, first thing!
It sounds like you may have more than one issue:- 1. No Master Fault Light and no warning buzzer when you turn on the key switch. 2. The fact that the oil pressure light on the EMS panel does not illuminate like the other three when you press the test switch. Some testing called for I think. Let me see if I can find an Electrical Schematic for it. If you get yourself an O&M Manual you will understand how the warning system is supposed to work. That’ll be half the battle right there.
I got the manual ordered. Checked all fuses and they all look good.
Take up KSH's offer of an Electrical Schematic. It'll help you figure out what does what. According to what I see the Low oil pressure switch changes state at around 10psi. At that point wire 405 Grey should be connected to ground via the switch and that extinguishes the light on the EMS Panel. So maybe a quick and dirty test would be to temporarily connect wire #405 Grey to any convenient machine frame ground with the key switch in the ON position and see whether or not the low oil pressure light on the EMS Panel comes on. FYI the original EMS panel is a 3T-9100, now replaced by 171-9816. If it requires a new decal then an English one is Part Number 6V-6502.
I just grounded 405 and no light for oil pressure flashes. The other lights flash when I flip the test switch but not the oil pressure indicator. The warning buzzer does work. I tried to start it and forgot to give it fuel and the buzzer sounded. I assume that was the low fuel pressure warning.
Sounds like time to invest in a replacement EMS panel then. Try Offroad equipment, not far from you and usually come up with decent pricing. Ask wherever you end up buying if it has a decal already installed or not, because if the answer is no then you will also need a decal.
A previous owner obviously didn’t trust the EMS panel because ther is already a trans temp gauge and an coolant temp gauge mounted on the machine. I believe I would feel more comfortable if I can find a port to put on a oil pressure gauge. Just above the oil sender there is a pipe plug. 3/8” maybe or metric. Anyway do you know if that is an oil port. By the way thank you very much for your help.
For a more accurate opinion snap a photo of the area around the oil pressure sensor showing the plug you mention and post it up.
There's nothing wrong with the EMS technology, it's been around over 30 years now. IMHO for "obviously didn't trust" I read "obviously didn't know and couldn't be bothered to find out/understand how it worked" - getting an O&M Manual is the first step in that process................... YMMV
I hope this posts ok.
I would say it's reasonably certain that plug has engine oil pressure behind it. Looks like 1/4" NPT thread at first sight but the plug would have to be removed to confirm that.
Off-road Equipment does not currently have a EMS but they are looking for one. Until then I will pull that plug and adapt a manual pressure gauge just so I can use the machine and be assured I have pressure. This fall and winter I will familiarize myself with the 943 as well as the manual. Again thanks for your help.
I plan on checking the oil pressure this weekend. Do you know what oil pressure I should expect to see when the 943 is at operating temp. At idle and at operating RPM. Thanks
So my operator/ service manual came in. I am learning a lot as I read through it. One thing I learned is that the two gauges, the trans temp and the coolant temp are factory gauges. so along with the EMS there are also gauges. I have a local company looking for a EMS and will get it in as soon as they find one. Meanwhile I am adding an oil pressure gauge to the factory cluster.
If your taking about the gauges above the foot pedals they belon there
Sorry I missed this. Oil pressure should be between 60-80psi at High Idle RPM when the engine is at normal operating temperature (around 200 DegF) Oil pressure should never drop below 15psi when the engine is idling with warm oil.
Not really the best cat model. I had plenty of issues with oil viscosity there though I did everything as was written in their manual.
Care to elaborate on the “viscosity issues”.?
Go on Machinery Trader type in the part number and it will show you who has the panel
This usually happens after 2 hours of operation. When I put the engine speed lever in the lock, the car was barely moving. I always had to run about 3/4 of the way to stop. The reverse speed drops to an almost complete stop after several hours of operation. The forward speed now drops in a similar way now, but it didn't happen at first. The problem manifests itself after the trans oil temperature reaches about 55-60 ° C. The previous owner suggested checking the VFD , but I don't think it has any sense.